#define _CRT_SECURE_NO_WARNINGS 1

#include<iostream>
#include<fstream>
using namespace std;

#define SQR(A) A*A

//void main() 
//{
//	int x = 6, y = 3, z = 2;
//	x /= SQR(y + z) / SQR(y + z);
//	cout << x << endl;
//}

class Date
{
	friend ostream& operator<<(ostream& _cout, const Date d);
	friend istream& operator>>(istream& _cin, const Date d);
public:
	Date(int year = 1900, int month = 1, int day = 1)
		:_year(year)
		,_month(month)
		,_day(day)
	{}
private:
	int _year;
	int _month;
	int _day;
};

ostream& operator<<(ostream& _cout, const Date d)
{
	_cout << d._year << "-" << d._month << "-" << d._day << endl;
	return _cout;
}

istream& operator>>(istream& _cin, const Date d)
{
	_cin >> d._year >> d._month >> d._day;
	return _cin;
}

//int main()
//{
//	Date d;
//	cin >> d;
//	cout << d;
//	return 0;
//}

#include <iostream>
using namespace std;
class cla 
{
	static int n;
public:
	cla() { n++;}
	~cla() { n--;}
	static int get_n() { return n; }
};

int cla::n = 0;
//int main() 
//{
//	cla* p = new cla;
//	delete p;
//	cout << "n=" << cla::get_n() << endl;
//	return 0;
//}


#include<iostream>
#include<string>
using namespace std;
class A 
{
	friend long fun(A s) 
	{
		if (s.x < 3) 
		{
			return 1;
		}
		return s.x + fun(A(s.x - 1));
	}
public:
	A(long a) 
	{
		x = a--;
	}
private:
	long x;
};

int main() 
{
	int sum = 0;
	for (int i = 0; i < 5; i++) 
	{
		sum += fun(A(i));
	}
	cout << sum;
	return 0;
}